There would be another beta during the following weekend (21st March till 23rd March). Pre-purchasing would enable you to be eligible for all the following betas including the upcoming one. If you want to try out the game first before confirming to pre-order, you can always get a key from a giveaway by Logitech Gaming or Curse, or somewhere else (lol).

NDA has been officially lifted from the betas, so feel free to discuss, livestream, record, take screenshots, whatever, about the game.